Update TPad.cxx (#6507)
Update TPad.cxx (#6507)

* Update TPad.cxx

Prevent integer divison by zero.

Tag @couet

* Update TPad.cxx
olifre/root,olifre/root,olifre/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root